JPH0227637B2 - - Google Patents

Description

[Detailed description of the invention]

[Object of the Invention] [Industrial Application Field] The present invention relates to a safety device for preventing a pinching accident in, for example, an electric window opening/closing device of an automobile, an electric roof panel, etc., and particularly relates to detecting the presence or absence of an abnormality. [Prior Art] In devices where the opening/closing mechanism is driven by an electric motor, such as the power window of a car, if a person's hand or the like is accidentally inserted into the opening while the mechanism is in the closing operation, it can become trapped. There is a fear. Conventional techniques for preventing this type of accident include, for example, Japanese Patent Publication No. 48-44445 and U.S. Patent No. 3689814.
number is known. The former uses a pressure-sensitive switch to detect the pressure applied during pinching, and the latter uses electrostatic induction between two electrodes to detect contact with the window frame. Additionally, a device is known that prevents pinching by detecting overload of an electric motor. [Problems to be Solved by the Invention] However, with conventional safety devices, the safety device does not operate until after an object touches the sensor, that is, after the actual entrapment occurs, so if for some reason there is a delay in activation, If this happens, an accident may occur even if safety devices are in place. This type of delay in operation can occur due to, for example, changes in the usage environment such as temperature and humidity, dirt on the detection unit, changes over time, and the like. Further, since the conventional security device operates according to the detection result of one detector, if that detector fails, the security device may not operate. For example, in the above-mentioned US Pat. No. 3,689,814, if a failure occurs in the oscillation circuit (oscillation stops), even if the window frame portion is touched, no signal is induced on the detection electrode side, so it cannot be detected and entrapment cannot be prevented. Further, in the above-mentioned US Pat. No. 3,689,814, contact can be quickly detected. However, since it is necessary to provide two electrodes for transmission and detection on the window frame and window glass, it is difficult to install it in a car or the like. To increase the reliability of detection, multiple detectors may be provided. However, when multiple detectors are installed, it becomes difficult to secure installation space for the detection parts (electrodes, etc.),
The installation work is difficult, and the configuration of the device is unavoidably complicated. The first objective of the present invention is to provide a highly reliable security device, and the second objective is to provide a security device that is easy to secure a mounting space for a detection unit, conduct electrical wiring, and perform installation work. do. [Structure of the invention] [Means for solving the problems] In order to achieve the above object, the present invention includes the following:
conductor; a conductor sharing means including at least three terminals, the first terminal of which is connected to the conductor; an oscillation circuit that generates a signal at a predetermined frequency; a part of the oscillation circuit is the conductor sharing means; a first signal generating means that is connected to the conductor through a second terminal of the conductor and stops oscillation under the influence of the reactance of the conductor; oscillates at a frequency different from that of the first signal generating means; a second oscillation circuit, a part of which is connected to the conductor via the third terminal of the conductor sharing means, and stops oscillation under the influence of reactance on the conductor side;
a signal generating means; a frequency mixing means whose input terminal is connected to the output terminal of the first signal generating means and an output terminal of the second signal generating means; at least one signal generating means connected to the output terminal of the frequency mixing means; a signal discriminating means, the signal discriminating means including a frequency selective filter and discriminating at least three states according to the presence or absence and frequency of a signal appearing at the output terminal of the frequency mixing means; Provide security measures for processing. [Operation] The conductor sharing means connects the first and second signal generating means in parallel to the conductor, that is, the detection antenna. The connection position between each signal generation means and the conductor sharing means is connected to a position where a change in reactance affects stopping of oscillation, such as in a tuned circuit, for example. Normally, a signal of a predetermined frequency is obtained at the output of each signal generating means, but when an element that changes reactance, such as a human hand, approaches or contacts the antenna, the signal is interrupted. For example, if the frequency of the first signal generating means is f1 and the frequency of the second signal generating means is f2, the output of the frequency mixing means usually includes f1+ in addition to f1 and f2.
Signal components with frequencies f2 and f1−f2 appear (f1>
f2). However, when the oscillation of the first signal generation means stops, the output of the frequency mixing means becomes only the frequency component of f2, and when the oscillation of the second signal generation means stops, the output of the frequency mixing means becomes the frequency component of f1. Only the ingredients. However, higher frequencies are more susceptible to reactance changes, so for example f1 > f2
In this case, if you gradually move your hand closer to the antenna,
First, the oscillation of the first signal generating means stops, and then the oscillation of the second signal generating means stops. Therefore,
Three types of states can occur at the output of the frequency mixing means. In other words, in the first state where the hand is not near the antenna, each frequency component of f1, f2, f1 + f2, f1 - f2 appears, and in the second state where the hand is close to the antenna, only the f2 component appears, and the antenna In the third state where the hand is in contact with, no signal appears. Therefore, the first and second states and the third state can be distinguished by the presence or absence of a signal at the output of the frequency mixing means, and the first state and the second state are They can be distinguished by differences in the frequency bands of the signals appearing at the output of the means. If a predetermined safety process is performed according to the identification result of such a state, it is possible to prevent a pinching accident by, for example, arranging the antenna near the opening/closing mechanism. In addition, it is possible to identify multiple abnormal states such as approaching states and contact states, so for example, by notifying abnormalities in approaching states, it is possible to avoid entrapment before it actually occurs. If the opening/closing drive is stopped upon detection of this, pinching can be reliably prevented, resulting in high reliability as a safety device. Furthermore, although it is possible to detect a plurality of such abnormal states, only one antenna is required, so it is easy to secure a space for installing it in a car, etc., and it is easy to conduct electrical wiring, installation, etc. When a failure occurs in this type of device, failures such as oscillation failure in the oscillation circuit are most likely to occur. However, in the present invention, if the oscillation circuit stops oscillating or if the frequency shifts, an abnormality detection output will be generated in the same way as when a hand approaches or touches the circuit, so even if a failure occurs, the circuit is designed to prevent pinching. It works, is extremely safe and reliable. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows one of the power window devices for an automobile implementing the present invention. Referring to Figure 1, this device includes a plurality of switches SW, a power window control circuit PWC, a detection circuit SEN, an antenna ANT, safety circuits SF1 and SF2, and an electric motor.
It has become familiar with MOT. The power window control circuit PWC, which has been used in the past, determines the state of the switch and generates signals (power supply) UP and DOWN for driving the electric motor MOT. The signal UP is normally 0V, and when the window glass is raised,
In other words, it becomes +12V when the window is closed. Signal DOWN
is normally 0V, and becomes +12V when the window glass is lowered, that is, when the window is opened. Vb is a constant voltage power supply line (+12V). Figures 2a and 2b show a car equipped with the device of Figure 1. Referring to each figure, in this example, the antenna ANT is arranged along the protrusion of the weather strip 2 on the vehicle body 3 side, which comes into contact with the tip of the window glass 1. Therefore, if a driver's hand, for example, is inserted into the movement range of the window glass 1, the hand will reach the antenna before the window glass 1 is fully closed.
You will approach or come into contact with ANT. FIG. 3 shows a specific configuration of the detection circuit SEN of FIG. 1. Referring to Figure 3, this circuit:
It consists of a shared circuit PC, oscillation circuits OSC1 and OSC2, amplifier circuits AM1 and AM2, frequency mixing circuit MIX, bandpass filter circuit BPF, and discrimination circuit DCN. The antenna ANT is connected to one end of the shared circuit PC, and the other two terminals of the shared circuit PC are connected to the oscillation circuits OSC1 and OSC2. The oscillation circuit OSC1 is a crystal oscillator using a crystal X1, and includes a capacitor C1 and an electric coil (transformer T
1) on the primary side). A line drawn out from a part of this tuned circuit is a shared circuit.
Connected to one end of the PC. The oscillation circuit OSC2 is
Similarly, it is a crystal oscillator using a crystal X2, and is equipped with a tuning circuit consisting of a capacitor C2 and an electric coil (the primary side of the transformer T2). A line drawn out from part of this tuned circuit is connected to another terminal of the shared circuit PC. The oscillation circuits OSC1 and OSC2 normally have frequencies corresponding to the natural frequencies of the respective crystals X1 and X2.
Each of f1 and f2 oscillates, but if a large reactance change occurs in each tuned circuit, each oscillation stops. In this example, the frequency is set to f1>2・f2. Since there is a relationship between the tuning frequency f, the capacitance C, and the inductance L of the tuning circuit as follows (2πf) ² = 1/(L・C), the higher the frequency of the tuning circuit, the better the tuning will be for the same reactance change. Easily changeable. In other words, the tuned circuit of the oscillation circuit OSC1 responds more sensitively to the same reactance change than the oscillation circuit OSC2. In this example, the oscillation circuit OSC1 stops oscillating when a person comes within a few centimeters from the antenna ANT, and the oscillation circuit OSC2 stops oscillating when the person comes into contact with the antenna ANT. The shared circuit PC separates the oscillation circuits OSC1 and OSC2 so that they do not affect each other, and connects them to the antenna ANT. Amplifier circuits AM1 and AM2 are each oscillation circuit OSC
It amplifies the signals (f1, f2) output by OSC1 and OSC2, and also functions as a buffer for the frequency mixing circuit MIX. The frequency mixing circuit MIX includes the oscillation circuit OSC1,
Combine the signals from OSC2. As a result, the circuit
The MIX output has two frequency components: f1+f2 and f1-f2 (when OSC1 and OSC2 are both oscillating)
appears. The bandpass filter circuit BPF is equipped with a ceramic filter CR1. Ceramic filter CR1 selectively passes only signals near frequencies f1-f2. Therefore, filter CF1
Normally, a signal (f1-f2) appears at the output of the oscillator, but when the oscillation of one of the oscillation circuits OSC1 and OSC2 stops, the frequency component of f1-f2 disappears, so no signal appears at the output terminal. The discrimination circuit DCN includes two sets of rectifier/smoothing circuits, 2
It consists of two analog comparators and an OR circuit. Diodes Da, Db and capacitor Ca constitute one rectifier/smoothing circuit, and diodes Dc, Dd
and capacitor Cb constitute another rectifier/smoothing circuit. Operational amplifiers OP1 and OP2 each operate as an analog comparator. diode
De, Df, transistor QA, etc. constitute an OR circuit. Therefore, each output terminal JA,
JB and JC output signal levels as shown in Table 1 below, depending on each of the three detection states of antenna ANT.

[Table] Indicates the level In other words, H on output terminal JA indicates approach detection,
The L of the output terminal JB indicates detection of either approach or contact, and the H of the output terminal JC indicates contact detection. FIG. 4 shows a specific configuration of the safety circuit SF2 of FIG. 1, and FIG. 5 shows a specific configuration of the safety circuit SF1 of FIG. 1. This will be explained with reference to FIGS. 1, 4, and 5. Each output terminal JA, JB, and JC of the detection circuit SEN is connected to each corresponding input terminal of the safety circuit SF1. Safety circuit SF
Each of the terminals JE1, JE2, and JE3 of the safety circuit SF2 is an input terminal, and is commonly connected to the output terminal JE of the safety circuit SF2. The circuit connected to the input terminal JB of the safety circuit SF1 includes transistors Q7 and Q8, a light emitting diode LED1 for display, resistors R22 to R26, and diodes D7 and D8. safety circuit
Terminal JD of SF1 is connected to a corresponding terminal of safety circuit SF2. The circuit connected to the input terminal JA includes transistors Q9 and Q10, and a light emitting diode for display.
It is equipped with LED2, resistors R27-R31 and diode D9. The circuit connected to the input terminal JC includes transistors Q11 and Q12, and a light emitting diode for display.
LED3, resistor R32 to R36, diode D
10, D11 and D12. The output terminal JS of the safety circuit SF1 is connected to the corresponding input terminal of the safety circuit SF2. As described later, the light emitting diode LED1 is
Lights up if there is no abnormality when closing the window glass, and light-emitting diode LED3 lights up when the detection circuit SEN detects "contact", and the light-emitting diode
Lights up when LED3 detection circuit SEN detects "contact". Safety circuit SF2 can be broadly divided into electric motors.
It is equipped with relays RL1 and RL2 that control energization of the MOT, a driver that controls energization of each relay, and a logic circuit that processes signals. Operational amplifier OP3
acts as an analog comparator. REG is
This is a voltage regulator for obtaining a predetermined power supply voltage (Vcc) from the power supply line Vb. The operation of the apparatus will be described with reference to FIGS. 1, 2, 3, 4, and 5. Under normal conditions, relays RL1 and RL2 are off (contacts connected to NC). When the driver instructs to open the window, the signal DOWN goes to +12V (at this time
UP becomes 0V), and relay RL2 to relay RL1
A current flows in the direction towards , which drives the electric motor MOT and drives the window in the opening direction. When the driver instructs to close the window, the signal UP goes +
12V (DOWN is 0V at this time), relay RL1
A current flows in the direction from to the relay RL2, thereby driving the electric motor MOT in the opposite direction when driving to open, and driving the window in the closing direction. Under normal conditions, the output terminal JA of the detection circuit SEN,
The levels of JB and JC are L, H and L, and the terminals JE, JE1, JE2 and JE3 are at high level H. Therefore, transistor Q7 is turned on and transistor Q8 is turned on. When instructing to close the window, terminal JD is +12V, so at this time current flows to light emitting diode LED1, causing it to light up. Also, transistor Q9 is turned off, and transistor Q1
0 is turned off, the light emitting diode LED2 is turned off. Further, since the transistor Q11 is turned off and the transistor Q12 is turned off, the light emitting diode LED3 is turned off. When the detection circuit SEN detects “approach”, the terminal
The levels of JA and JB change to H and L, respectively. This turns off transistor Q7, turns off transistor Q8, and turns off the light emitting diode.
LED1 turns off. Further, the transistor Q9 is turned on, and the light emitting diode LED2 is turned on. This notifies the driver of the danger. However, the driving state of the electric motor MOT does not change. When the detection circuit SEN detects "contact", the levels of each terminal JA, JB and JC become H, L and H. Therefore, the light emitting diodes LED1 and LED2
The state is the same as when "approach" is detected. When the level of the terminal JC becomes H, the transistor Q11 is turned on. As a result, the light emitting diode LED3 lights up and the terminal JS goes to low level L. The output terminal of the operational amplifier OP3 is normally at a low level L, but when the terminal JS becomes L, it is inverted to H. This turns on transistor Q1. When transistor Q1 is turned on, transistor Q2 is turned on, transistor Q3 is turned on, and relay RL1 is energized to the on state. Further, since the terminal JE maintains the low level L regardless of the state of the transistor Q1, the driver circuit that energizes the relay RL1 is latched in the on state. Further, when the transistor Q1 is turned on, the transistor Q4 is turned on, the transistor Q5 is turned on, and the relay R12 is energized to the on state. Note that when transistor Q1 is turned on, capacitor C3 is charged, which lowers the base potential of transistor Q4. Therefore, even after transistor Q1 is turned off, there is a voltage between the base terminal and emitter terminal of transistor Q4 for a predetermined period of time. A predetermined on signal is applied, and transistor Q4 maintains the on state. When relays RL1 and RL2 are both turned on, current flows from relay RL2 toward the contact point of RL1, thereby driving electric motor MOT in reverse in the window opening direction. In this state, whether the terminal JS returns to high level H or
Alternatively, when the discharge of capacitor C3 is completed, transistor Q4 is turned off, transistor Q5 is turned off, and relay RL2 returns to the off state. relay RL
2 is turned off, no current flows to the electric motor MOT, and the window opening operation stops. Since the driver circuit that energizes relay RL1 is latched on, relay RL1 remains on. Therefore, the window driving operation remains stopped. Turn the driver UP switch back to OFF, and the signal UP is
When the voltage returns to 0V, the level of the base terminal of the transistor Q3 is inverted to L via the diode D3. This turns off transistor Q3, turns off relay RL1, returns the level of terminal JE to H, and releases the latch. Once the detection circuit SEN detects a "contact" state, until the latch is released, that is, until the UP switch is turned off, the terminal JE is at a low level L, so transistors Q10 and Q12 are in the on state. become. Therefore, during that period, the detection circuit
Even if SEN no longer detects “contact” and “proximity” conditions, light emitting diode LED2 and LED
3 maintains the lighting state. In the above embodiment, an alarm is displayed when "approach" is detected, and the motor is reversed/stopped and an alarm is displayed when "contact" is detected, but either "approach" or "contact" is detected. Once detected, motor control may be switched. To do this, the safety circuit SF1 may be modified as shown in FIG. Referring to FIG. 6, in this embodiment two diodes D1 are connected to the collector terminal of transistor Q9.
3 and D14 are additionally connected, and the anode terminal of diode D14 is connected to terminal JS. Therefore, the output terminals JA and
When any of JC becomes high level H, the terminal JS is set to low level L, thereby performing the window opening operation. This embodiment is even safer because the danger is avoided before a "contact" situation occurs. FIG. 7 shows another embodiment of the invention.
In this embodiment, a microcomputer CPU is used for control. Similar to the previous example,
Relay RL1 for controlling electric motor MOT
and RL2, and a light emitting diode LED1 for display,
LED2 and LED3 are provided, and these are connected to the microcomputer via driver DV2.
Connected to the output port of the CPU. Power supply unit PW generates constant voltage Vcc from power supply voltage Vb. FIG. 8 shows the operation of the microcomputer CPU shown in FIG. 7. This will be explained with reference to FIG. Note that this operation is substantially the same as that of the apparatus shown in FIG. 1 above. When the power is turned on, initial settings are performed first. That is, it clears the contents of memory and
Set MOT to stop state, light emitting diode LED
1. Clear the display of LED2 and LED3. Next, check the status of the signals UP and DOWN. If the signal DOWN is on level (+12V),
To drive the motor MOT in the direction of window opening operation,
Set output ports P4 and P5, signal DOWN
This state is maintained until it reaches the off level (0V). When the signal DOWN becomes off level, output ports P4 and P are connected so that the motor MOT stops.
5 and check the signal UP and DOWN again. When the signal UP becomes on level, check terminal JB and if it is H, that is, there is no abnormality,
Set output ports P4 and P5 so that the motor MOT is driven in the window closing direction, and connect the light emitting diode
Set LED1 to light up and repeat the check for signal UP. If the terminal JB becomes a low level L while the signal UP is on level, then check the status of the terminals JA and JC. If either terminal JA or JC is at low level L, that is, in the "approach" state, light emitting diode LED2 is set to light up and the motor is turned on.
MOT is set to window closing drive state and signal is UP again
Repeat the check. When terminal JB is at a low level, if both terminals JA and JC are at high level H, that is, in the "contact" detection state, output ports P4 and P5 are set so that the motor MOT is driven in the window opening direction, and the light emitting diode is
Set LED2 and LED3 to turn on, LED1 to turn off, and start the timer. When the timer expires, set the motor MOT to a stopped state and wait until the signal UP turns off. When the signal UP turns off, set the light emitting diodes LED2 and LED3 to OFF and repeat checking the signal UP and DOWN again. FIG. 9 shows a modification of FIG. 8. In this modification, substantially the same operation as the embodiment shown in FIG. 6 is realized using the apparatus shown in FIG. This will be explained with reference to FIG. When the power is turned on, first perform the initial settings, then check the signals UP and DOWN. The operation when the signal DOWN turns on is the same as in the case of FIG. When signal UP turns on, check terminal JB,
If it is H, that is, there is no abnormality, the motor
Set output ports P4 and P5 so that the MOT is driven in the window closing direction, and turn on the light emitting diode LED.
Set 1 to turn on and repeat checking only the signal UP. If the terminal JB becomes low level L while the signal UP is on level, then check the state of the terminal JC. If the terminal JC is at low level L, that is, in the "approach" state, output ports P4 and P5 are set so that the motor MOT is driven in the window opening direction, the light emitting diode LED2 is turned on (LED1 is turned off), and the timer is started. Start. Also, if the terminal JC is at a high level H, that is, in the "contact" state, the motor
Set output ports P4 and P5 so that MOT is driven in the window opening direction, and light emitting diode LED3.
lights up (turns off LED1) and starts the timer. After starting the timer, when it times out, set the motor MOT to the stopped state, wait until the signal UP turns off, and when it turns off, set the light emitting diodes LED2 and LED3 to off, and turn it on again. Repeat checking the signal UP and DOWN. In the above embodiment, a light emitting diode display is used as the notification means, but an alarm sound generator using a buzzer may also be used, for example. In addition, the operation for notifying may include blinking the display means or changing the display color, and in the case of an alarm sound, the frequency, tone,
It may also be possible to change the volume or the like. [Effects] As described above, according to the present invention, since a plurality of abnormal states such as approach and contact are detected, double security measures such as an alarm and abnormal stop of the drive can be performed, and reliability is high. Furthermore, since one antenna is shared by a plurality of circuits, it is easy to secure mounting space, electrical wiring, and mounting work for the detection section. Further, even when the oscillation circuit fails, the same detection signal output as when there is an abnormality can be obtained, so it is extremely safe and accidents such as pinching can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. Fig. 2a is a side view showing a car equipped with the device shown in Fig. 1, and Fig. 2b is a side view of a car equipped with the device shown in Fig. 1.
It is a sectional view taken along the b line. Figure 3 shows the detection circuit in Figure 1.
FIG. 3 is an electrical circuit diagram showing details of SEN. Figure 4 shows
2 is an electric circuit diagram showing details of the safety circuit SF2 of FIG. 1. FIG. FIG. 5 is an electrical circuit diagram showing details of the safety circuit SF1 of FIG. 1. FIG. 6 is an electrical circuit diagram showing one modification of the circuit shown in FIG. 5. FIG. 7 is a block diagram showing another embodiment. FIG. 8 is a flow chart showing the operation of the microcomputer CPU shown in FIG. FIG. 9 is a flowchart showing a modification of FIG. 8. 1: Window glass, 2: Weather strip, 3: Vehicle body, ANT: Antenna (conductor), OSC1: Oscillation circuit (first signal generation means), OSC2: Oscillation circuit (second signal generation means), AM1, AM2 : Amplifier circuit, PC: Shared circuit (conductor common means), MIX:
Frequency mixing circuit (frequency mixing means), BPF: band pass filter circuit, CF1: ceramic filter, DCN: discrimination circuit, SF1, SF2: safety circuit (security means), SEN: detection circuit, MOT: electric motor, RL1, RL2 :Relay, LED1, LED2,
LED3: Light emitting diode, X1, X2: Crystal,
CPU: Microcomputer.

Claims (1)

[Scope of Claims] 1. Electric conductor; Electric conductor sharing means including at least three terminals, the first terminal of which is connected to the electric conductor; Includes an oscillation circuit that generates a signal at a predetermined frequency;
A portion of the oscillation circuit is connected to the second conductor sharing means.
a first signal generating means that is connected to the conductor through a terminal and stops oscillation under the influence of the reactance of the conductor; an oscillation circuit that oscillates at a frequency different from that of the first signal generating means; a part of the oscillation circuit is connected to the conductor through the third terminal of the conductor sharing means, and stops oscillation under the influence of reactance on the conductor side. ; frequency mixing means whose input terminal is connected to the output terminal of said first signal generating means and to the output terminal of said second signal generating means; at least one frequency selectivity connected to the output terminal of said frequency mixing means; Signal discriminating means including a filter and discriminating at least three states depending on the presence or absence of a signal appearing at the output terminal of the frequency mixing means and the frequency; and performing predetermined security processing according to the discrimination result of the signal discriminating means. A security device comprising: security means; 2. The second terminal and the third terminal of the conductor sharing means are connected to a part of the tuning circuit of the oscillation circuit of the first and second signal generating means, respectively. Safety device as described. 3. The safety device according to claim 1, wherein the ratio between the oscillation frequency of the first signal generation means and the oscillation frequency of the second signal generation means is set to 2 or more. 4. The safety means includes a motor drive control means and a notification means, and when the signal output of the first signal generation means is cut off, the notification means is energized, and the signal output of the second signal generation means is cut off. 4. The safety device according to claim 3, wherein the safety device switches the driving state of the motor. 5. The safety means reverses the driving direction of the motor when the signal output of the second signal generation means is cut off.
A security device according to claim 4. 6. The safety means includes a motor drive control means and a notification means, and when the signal output of at least one signal generation means is cut off, the safety means energizes the notification means and switches the driving state of the motor. The safety device described in Scope 1.